Fluid-pressure-operated tool.



PATENTED MAY l2, 1908.

O. H. JOHNSON. FLUID PRESSURE OPRATED TOOL.

APPLIGATION FILED Nov.19, 1902. BENEWED SEPT. s. 190e.

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` (lill/10110011111 W'lzegsses No. 887,095. PATENTBD MAY 12, 1908.v

c. H. JOHNSON.

FLUID PRESSURE OPBRATED TOOL.

APPLIOATION FILED Nov.19, 1902.` BBNBWBD SEPT. e. 190e.

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vically prevented w UNITED STATES PATENT oEEioE.

S/HARLES H. JOHNSON, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, T() THE PITTSBURG -PNEUMATIC COMPANY, OF CANTON, OHIO, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

FLUID-PRESSUREI-OPERATED TOOL.

Patented May 12, 1908.

Application led November 19, 1902, Serial No. 131,948. Renewed September 6, 1906, Serial No. 333,442.

To all whom it may concern: Be it known that I, CHARLES H. JOHNSON, a citizen of the United States, residing at Chicago Heights, county of Cook, State of Illinois, have invented a certain new and useful Improvement in Fluid Pressure Operated Tools, and declare the following to he a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a art of this s eciflcation. My invention. re ates generally to fluid ressure o erated tools, and more particuarly to va ve mechanism controlling the admission and exhaust of fluid pressure to the cylinder. y

.In fluid pressure tools it is desirable that the valve controlling the supply and exhaust of pressure to the ends of the c 'linder should be operated to cut off the su p y from the res ective sides of the piston efore it reaches t e end of its stroke, and it is also desirable that the valve should be quickly shifted from one position to the other, and when shifted, I

positively held by a preponderance of pressure i-n each position until the piston reaches the predetermined point in its stroke, when the supply and exhaust of fluid pressure to the respective ends of the cylinder should be reversed.

Fluid pressure operated tools of the character referred to are of such power that if the throttle valve is open when the snap or die is out of contact with the object boing worked upon, the snap will be violently ejected from the cylinder and thrown a considerable distance owing to thel impact of tho piston therewith. It is therefore desirable that the ro ciprocation of the iston should he automatlien the snap is not in contact with an object.

An object of my invention is to provide a fluid pressure operated tool in which the supply and exhaust of pressureto the respective ends of the cylinder are controlled by a piston valve, the reciprocation of which to its con.- trolling ositions will he quickly :ind certainly accom ished and which when shifted will bo firmlyield in each position until again shifted by the piston reaching the proper predetermined point in its throw.

y A further object of my invention is to construct-a lluld pressure operated tool of the' cna..rcter referred to in which the front end.

provide a fluid pressure o erated tool of the type referred to which wil be comparatively simple in cons truction and eflicient in operation.

l My invention generally stated consists in a cylinder within which a piston is reciprocated by the supply and exhaust of pressureto its opposite sldes, the su ply and exhaust of pressure being contro ed by a differential piston valve having radial surfaces one of which is constantly exposed to fluid pressure admitted to the valve casing from the supply port to .retain the valve in one position, the valve being moved to such osition by exposing an end thereof't fluid) pressure passing from one end of the cylinder, said valve having a second radial surface of reater effective area than the first surface w ich is exposed to pressure admitted to the valve casing from the supply port to move the valve to its opposite position, said second radial surface being exposed to fluid pressure in one end of the cy in'der to retain the valve in its second position and being relieved of pressure when said end of the cylinder communicates with the exhaust port, thereby permitting the valve to be retained in its first position by the constant pressure exerted on the first radial surface.

My invention further consists in a fluid )ressure operated tool in which a button is interposed between the iston and the die to transmit the impact of t e former to the latter and to control an exhaust port leading from the front of the cylinder, the button being automaticall moved to open the exhaust port to relieve t e pressure under the piston when the die is disengaged from an object, thereby preventin the die from being ejected from the cylin( er by. the piston and also discon tinuing the reci rocation of the piston.

The invention will e more fully described hereinafter with reference to the accompanying drawings in which the same is illustrated as embodied in a convenient-and practical form, 'and in which-- Figure 1 is a longitudinal vertical section A still further object ofmy invention is to of an embodiment of my invention taken on line 1---1, Fig. 2, the parts being shown in the positions they assume when the die is in contact with an object; Fig. 2a horizontal sectional view of my invention taken on line 2 -2, Fi 1,' the parts being shown in the positions tliey assume when the die is rlisenl gaged from an object; Fig. 3 aisectional view on an enlarged scale through the valve casing; Fi 4 a v1ew similar to Fig. 3 showing the va ve in its second position; Fig. 5 a detail sectional View taken'on line 5 5, Fi 3; and Fig. 6 a longitudinal section throug the valve.

The same reference characters are used to indicate the same parts inthe several igures of the drawings. A

Reference letter A indicates 'the handle of the tool which is provided with a tubular extension A surrounding the back end of the cylinder C. A lever A* is pivotally supported in the handle A and is provided with a lug a* adapted to engage the end of a valve stem b4. The throttle valve is located within a cylindrical valve casing B2 which is in screw threaded enga ement with an opening B in the valvehan( le. A spring Ba 1s interposed between the valve and the cylindrical valve casing and normally retains the valve in po- '.spect to the handle.

l leads from the chamber C4 sition to close the ports b2 formed through the valve seat. A passage B is formed 1n the handle A and is adapted to be connected with a conduitleading from a source of fluid pressure.

The cylinder C is provided with a b llshing c one end of which 1s enga ed b a cylinderv head C which is secured wit in t e cylinder. The handle is retained upon the cylinder by means of an annular flange Alin, terpos'ed between the end of the cylinder and a peripheral flange on thecylinder head C. Any suitable means may be provided for preventing the disengagement lof vthe cylinder head from the cy inder, lsuch means bein 'Shown as consisting in a spring bolt A5 which en ages the periphery of the cylinder head. an prevents the same from rotating with re- The end of the cylinder opposite to the cylinder head C is interiorly screw threaded and is engaged by a ferrule G. A snap or die H is removably supported within the ferruley G and is yieldingly retainedthereinby means of` a spring ring g seated within an annular oove formed in the interiorsurface ofthe gdrrule near the outer end thereof. The shank of the die H is reduced, as shown at h, forming shoulders at either side of such reduced portion which serve as stdps to engage-thel springring g. A chamber 4 is formedl in the end of theylinder between the ferrule and the end of the 'bushing c.v Within the chamber C" is located a button L having a reduced portion -L of a diameter"substantially the\ same as the interior diameter of the ferrule within which it extends.. An exhaust port 'end ol' the bushing is and is normally when the same is in the position shown inFig'. l

1. A spring C3 is locate between the bushing c and the cylinderC 'and engages the button L'. The tension of the spring tendsV to move the button to the position shown in Fig.v 2 in which the exhaust ort l is opened.

A cylindrical va ve casing A2 formed integrally with the handle'is located transversely beneath the back end of the cylinder. The valve casing is rovided with a series of annular grooves wit 1 which communicate ports a', a2, (1.3, and a, registering with orts c', c2, ci, and c4 former in the cyliniler C. Exhaust ports a5. and u. are formed in the opposite ends of the valve casing. Supply ports a. are located near the center of the valve casing and communicate with a passage A formed in the handle extending from a point above the throttle valve.

(l2 isa passa fe running longitudinally of the cylinder an( connecting the port (1.2 with the raduated ports c2.A I

The portiel leading to a point 't7 wi-thin the. cylinder slightly further away from the chamber (Il than the length of the piston K 'as shown in Fi 2. The port cz communicates with the c index' near the back end thereof. A p urality of such ports ci'of grarllally increasing size are preferabl employed, as shown'in Figs. 1 and 2. T e port c3 is extended to form a passage7 as shown in Fir '5,4

preferably i which communicates with the interior of?, the

cylinder at a point c5 'located thesame distance from the rear and of the cylinder as the rear ort of the series c2. The ort c4 comf munlcates with a passage lea( ing to the front end of the cylinder. f

A bushing E is locatedwithin the valve casing A2 and is retained therein by means ofthe cap A3 which closes the o en end ofthe. valve casing. One vend of t le bushing is, closed by'means of a disk E while the other cen-tricv ortion E2 whi reduces the bore ofV the busliing. The bushing is provided-with series of ports e, e', e2, e3, e4, and e.5 which register with the. corresponding ports a, a?,` a3, a4, and a5 formed in the valve casing.

A differential pistonvalve D is located.- within the bushing andA controls' the ports therethrou h.

plrovided with a conl C 11,3l

The end D" of vthe valve is I hollow an' is provided with ports ft", connecting theexterior surface with the hollow interior. Av shoulder D is formed on the valve by reducing the dia1neter,' as cle'arl shown in Fig'. 6. -The end of the valve D2 1s also hollow and is closed by means of a plug D5.. An annular lange D4 of slightl greater diameter than the annular 4shouldler Ds is may be readily assembled by inserting .thel

valve in the bushing prior to placing the end cap E on the bushing and subsequently inf serting the bushing with the valve therein into the valve casing. The cap A is then inserted preferably by means of cooperating screw threads into thel end of the valvecasing, thereby closing the saine.

The operation ol'niy invention is as follows: 'lhe lever A4 is forced forwardly and thereby oscillated about its ivot so that the lug at thereon through the interposed valve stein depresses the throttle valve uncovering the ports b2. Fluid under ressure lthen flows from the source thereo through the coupling B, thence through the orts b2 to the passageway A7 which communicates with the annular supply port a located near the center ofJ thevalve casing A2. When the valve is in the position indicated in Fig. 3 fluid pressure flows from the supply port a inwardly through the ports e in the bushing around the reduced portion of the valve, then outwardly through the port e2, in the bushing, the port (t2 in the valve casing, thence through the first of the series of ports c into the back end of the cylinder. As the piston successively uncovers the ports in the series c2 t'he impetus of the piston is accelerated owing tothe orts in the series cl being gradually larger in iameter.

When the piston is to the rear of, or-covers the port c7, and the valve is in the position shown in Fig. 3 both ends of the valve are exposedI to atmospheric pressure, D2 directly through ports o and D through the front end of theV cylinder by way of ports and passages 'i, e', af, c', c7, c", a, e4 and a, while the shoulder D3 and radial surfaces d and d4 arc` all exposed to the same pressure and consequently the valve is retained in this position owing. to 'the area of the radial siii'- face d being greater than the difference in area between the radial surface of the shoulder D" and the radial surface d.

When the piston has nearly reached the limit of its forward stroke the port c7 is uncovered and fluid pressure then flows through the passage comuninicating with said port to the port c, thence through the port (1. in the valve casing, thc ports e in the bushing, through thc ports d to thc hollow interior of the end l) of the valve. 'lhc tinucs the'rcriprocatio-ir of the piston.

tion sh'own in Fig. 3 to that shown in Fig. 4. This movement of the valve takes lace owing to the area of the end D thereof eing greater than the resultant area exposed to pressure in the opposite direction.

When the valve is in the osition indicated in Fig. 4 .the rear end of) the cylinder is placed in communication with the exhaust through the following ports and passages.; c2, a2, e2, d and a5. Flui pressure is then admitted to the front end of the cylinder to move the iston towards the hand e through the following ports and passages; a, e, d, 112, e4, a4, and port c, which communicates with the front end of the cylinder.

When the piston covers port c'rx fluid pressure passing through leakage ort diy cannot escape to the atmosphere an acts against the radial surface d, and consequently as the area of the radial surfaced4 is greater than the difference in area between the radial surface d3 and the shoulder D3 the valve is moved to the position shown in Fig. 3 i'nasmuch as the opposite ends of the valve are exposed merely to atmos heric resi-:iure d1- rectly through ports w" an a, hile a leakage groove d5 is shown the same maybe omitted without interfering with the' 'o eration of the valve as the leakage aroun the annular flange D4 is sufficient to effect the reverse movement of the valve from the position shown in Fig. 4 to that shown in Flg. 3. Pressure is now admitted for the forward stroke through orts e, and a? and the graduated port c2, and) the valve is retained in position shown in Fig. 3 by pressure in the. cylinder, which backs u in passage c and acts on the radial surface d4).

When the snap or dielis'forced against an object the spring C3 is compressed owing-to the engagement between the adjacent end of the die I I and the reduced portion L of the button L. The exhaust port Z isconse quently closed when the button L is in position to receive the im act of the iston and transmit the same to t ie die H. hen howover the snap or die Il is out of engagement l with an object the spring C3 expands, thereby forcing the button to the position shown in' Fig. 2, which in turn moves the die outwardly, as indicated in said figure. The exhaust port l is then uncovered by the button which permits the fluid under pressure to exhaust from the front end of the cylinder to thc atiiiosphere and consequently discon- The movement of the die to the position shown iii Fig. 2 owing to the expansion of the spring removes the .rame from the range of impact ol' the piston and consequently prevents the die from being ejected from the tool when it is disengaged from aiiobject.

. From the foregoing description it will be observed that, l have invented an improved f valve is consequently moved lroin the -posii fluid pressure operated tool employing a pis- 130 eating with one end of the cylinder and'a ort i ton.

provided a fiuid pressure actuated tool the.

ton valve for controlling the supply and exhaust of fluid ressure which is moved to one position by uid pressure admitted to the valve casing -through a passage leading from the interior of the cylinder, and retained in said positionhy exposing one surface of the val-ve to the atmosphere through the cylinder, while a second surface is ex osed to constant pressure from the supp y port and which is moved to and retained 4in its other posit-ion'by the pressure of an accumulation of' fluid upon the first surface the latter being then cut off from the atmosphereby the pis- It will'be further observed that I have front end of which is automatically( connected with an exhaust port when the to,'ol is disen-A gaged from an object, thereby dispontinuing the re'r-.iprocation of the piston, and in which the sna or die is automatically moved out of range ofiinpact of the piston when the tool is out of engagement with an object.

While I have described more. or less precisely the details of construction I do not wish to be understood as limiting myself thereto, as I contemplate changes in form, the proportion of parts, and thel substitution of equivalents, as circumstances may suggest the spirit of .my invention.

f or render expedient, without departing fl'rom Having now fully described my inventionl what I claim as new and desire to Letters Patent is` 1. In a fluid ressure operated tool, the combination witfi a cylinder, of apiston reciprocated therein, a valve casing having a series of ports of graduated sizes communisecure by communicating with the opposite end o the cylinder, a differential piston valve in said casing controlling the su pply and exhaust of pressure'through said ports to the opposite ends of the cylinder. y

2. In a fiuid ressure operated tool, the combination witili a cylinder, of a piston adapted to reeiprocatetherein, a valve casing having ports communicating with said` cylinder, a differential piston valve within said casing controlling the supply and'exhaust of' fluid pressure to and from the cylin@ der, a radial surface on said valve constantly exposed to fluid pressure tending to move the va ve to one position, a second radial surface larger than the first on said valve adapted to be alternately exposed to fiuid pressure in the valve casing and to the atmospherethrougli the cylinder, said valve casing having assages leading therefrom to the interior o the cylinderA controlled by the pistonto admitl fiuid pressure to the valve casing to move the valve, into said position, 'and to expose said second radial surface of the valve to atmospheric pressure to efl'ect the retention of the valve inl said positioi., the movement of the i. valve to and its retention inits other position combination wit ressure exerted upon'saidsecond radial surace when the atmospheric communication from the valve casing through the cylinder is cut off by the iston.

In a fluir ressure operated tool, the a cylinder, of a piston adapted to reciprocate therein,'a valve casinfr having ports communicating with said cylinder, a differential piston valve within said casing controlling the supply and ex liaust of Huid ressure to and from the cylininder, said cy inder and valve casingy having communicating passages through one of .which fiuid pressure is admitted to the casing lfrom the cylinder and through the other of whichvfluid pressure is exhausted through the cylinder from'the casing thereby effecting the movement of the valve. i

4. In a fluid ressure operated'tool, the combination witi a cylinder, of. a piston having' ports communicating'with said cylinder, a diHereiitial piston valve within said casing controlling the supply and exhaust of fluid pressure to and from the cylinder, a surface on said valv,e constantly exposed to 'fluid pressure, vand two other surfaces on said valve one of which is alternately exposed 'to fluid 'ressure from the cylinder and to the atmosp iere through the valve casing While the other is alternately exposed to the atmosphere through the cylinI vsure in the valve casing. 5. In a fiuid pressure operated tool, the combination with av cylinder, of a reciprocatder and to fluid presadapted to reciprocate therein, a valve casing ing piston therein, a die removably fitted in the end of said cylinder and yieldingly retained therein, a button interposed between said piston and die for transmitting the impact ofthe piston to the die, and means for automatical ton to the die.

6. In a fluid ressureoperated tool, the combination wit a cylinder, of a reciprocat y lpreventing the im lact of' the" piston from being communicated y the buting piston therein, a die removably fitted in -1 the end of said cylinder, a'button inter osed between said piston and die to transmit the impact of the former to the latter, a stop extending'into the cylinder to limit the move* ment of the button, and means for forcing the button against said stop when the die is not in contact with an object. -75 In a fluid ressure operated tool, the combination wit a cylinder, of a reciprocating piston therein, a die removably fitted y within said cylinder, a button interposed between said into theI cy inder to limit the movement 0f the button, and a spring engaging said butthc die is not in contact with an object.

In a lfluid Eessure operated tool, the combination wit a cylinder having a port iston and die, a stop extending ton to force the same against said stop when said cylinder, a` die movably fitted in said combination with a cylinder, of a reciprocatva ve havin .and thereby moves said button to uncover the combination with a cylinder, of a reciprotherethrough, of a reciprocating piston in l said cylinder, a die movably fitted in said l cylinder, and a spring actuated buttony closing said port through the cylinder when the die is forced against an object and'uncover- 1 ing said port when the die is not in contact with an object.

9. In a fluid combination wi"V therethrough, of a reciprocating piston 1n plhessure` operated tool, the .Y fig-cylinder having a port cylinder, a button located within the end of said cylinder and interposed between said piston and die, a spring enga ing-said button whereby the die when force against an oblect compresses said spring and moves said utton over said port and when th'e'die is disengaged from-an object said spring expands the port.

. 10. Ina fluid pressure operated tool, the combination with a cylinder'having an exhaust port therethrough, of a reci rocating iston in said cylinder, a die mova ly fitted 1n the end of said cylinder, and a spring actuated button interposed between lsaid piston and 'die for automatically closing and opening said exhaust port when the tool is respectively pressed against and out of contact with an obj ect.

1 1. In a fluid pressure actuated device, the

ing piston withinthe cylinder, a valve chamber, a valve within said chamber controlling the supply and exhaust of motive fluid to and from said cylinder to reciprocate the iston, said cylinder having a pressure supp y passage controlled by the piston and leadingl thereto from the Valve chamber for exhaustin fluid pressure from thehamber, and said a surface against which pres-v sure accumu ates when said passage is closed to the atmos here. p

' 12. In a uid pressure actuated device, i

catino piston within the cylinder, a valve chamber, a valve within said chamber controlling the supply and exhaust. of motive fluid to and from said cylinder to reciprocate the piston, said cylinder having an exhaust ,the supply and :and from said cylinder to reciprocate the passage and a pressure supply passage connecting the same with the valve .chamber said passages controlled by the iston to ex! haust fluid pressure from t e 'chamber through the cylinder, and said valve having ca surface a ainst which pressure accumulates when sai( 'passages are closed by the piston.

13. In a fluid ressure actuated evice, the combination with a cylinder, of a reciproeating1 piston chamber, a valve within said chamber controlling the supply and exhaust of motiveA fluid to and from said cylinder to reciprocate' the fiston, said cylinder having a pressure y passage controlled by the piston and lea( ing thereto from the valve chamber for exhaustingy fluid pressure from the chamber, and said valve having a surface a ainst which pressure accumulates when sai passage-is closed to the atmosphere,'to move the valve 70 to a certain position. y

. 14. In a fluid pressure actuated device, vthe combination with a cylinder, of a reciprocat-v ing piston within the cylinder, a valve chamber, a`valve within said exhaust' of motive fluid to piston, said cylinder and valve chamber eing connected by a passage through which fluid pressure is exhausted through the cylinder to control the valve.

15. In a fluid pressure actuated device, the combination with a cylinder, of a reciprocating piston within the cylinder, a valve chamber, a valve within said chamber controlling the supply and exhaust of motive fluid to and from said cylinder to reciprocate the piston, said cylinder and casing having ports and passages thro'u h which the reciprocation' of the valve is e ected comprising, a passage within the cylinder, a valve A60 chamber controlling 75 from the chamber 80 accumulates when 

